The present disclosure relates to processes for producing toners. In embodiments, flow aids are added to improve flow characteristics of a toner, thereby enhancing overall drying time, reducing the amount of coarse particles and improving yield, without adversely affecting fusing and charging of the toner particles.
Numerous processes are within the purview of those skilled in the art for the preparation of toners. Emulsion aggregation (EA) is one such method. Emulsion aggregation toners may be used in forming print and/or electrophotographic images. Emulsion aggregation techniques may involve the formation of a polymer emulsion by heating a monomer and undertaking a batch or semi-continuous emulsion polymerization, as disclosed in, for example, U.S. Pat. No. 5,853,943, the disclosure of which is hereby incorporated by reference in its entirety. Other examples of emulsion/aggregation/coalescing processes for the preparation of toners are illustrated in U.S. Pat. Nos. 5,902,710; 5,910,387; 5,916,725; 5,919,595; 5,925,488, 5,977,210, 5,994,020, and U.S. Patent Application Publication No. 2008/0107989, the disclosures of each of which are hereby incorporated by reference in their entirety.
Polyester toners have been prepared utilizing amorphous and crystalline polyester resins as illustrated, for example, in U.S. Patent Application Publication No. 2008/0153027, the disclosure of which is hereby incorporated by reference in its entirety.
One issue with emulsion aggregation toners is that the drying process utilized to form the particles may result in the dried toner becoming compacted; this may be partly because the toner particles have strong cohesive forces. The toner may thus stick to both itself and the drying apparatus, thereby reducing the overall toner yield and higher toner unit manufacturing cost (UMC), which may thus result in lost profits. One way to minimize the compaction problem is to equip the drying apparatus with impact vibrators or some similar apparatus; however, even with these standard automated methods in place, the toner may not be easily loosened. Thus, the toner yields remain low.
It would be advantageous to provide a more efficient process for recovering emulsion aggregation toners from the apparatus utilized in their formation.